Photon Echo in Uniaxially Stressed Germanium with Antimony Donors

TL;DR

This study demonstrates photon echo in stressed germanium with antimony donors, showing that uniaxial stress enhances coherence times by valley splitting, which is promising for quantum information applications.

Contribution

It reveals how uniaxial stress in germanium improves photon echo coherence times through valley splitting of donor states.

Findings

Photon echo observed in stressed germanium with Sb donors

Uniaxial stress increases coherence time to 300 ps

Valley splitting enhances photon echo signals

Abstract

Photon echo is observed in n-type Ge uniaxially stressed along the [111] crystallographic direction, with a coherence relaxation time of 300 ps. The nonlinear polarization responsible for the effect originates from antimony donors. Uniaxial stress induces valley splitting of the donor states, substantially enhancing the coherence time and enabling the observation of photon echo.